The brew, which is especially popular in Asia, where cancer is rarer than in the West, contains antioxidants that are known to prevent skin cancer in mice and may prevent it in humans, a report summarizing recent research into green tea said.

Previous research has suggested substances in green tea called polyphenols can kill tumor cells and may starve cancerous growths by limiting blood vessel growth around them.

“Based on epidemiological and mouse models, we can say drinking four or five cups a day may be very helpful for protection,” the report’s author, Santosh Katiyar of Case Western Reserve University, said in a phone interview.

But he cautioned that green tea was a preventive step, not a cure, for skin cancer.

“It is a prevention. … As long as I take it, I am protected,” said Katiyar, who drinks two cups of green tea a day.